A systematic review and Bayesian analysis of the adverse effects of dienogest

Background and objective: Endometriosis and adenomyosis are two common diseases that impair women's health, and dienogest is one of the pharmacologic treatments which is the first-line therapeutic option for patients with pelvic pain and individuals who have no desire for immediate pregnancy. The goal of this study was to summarize the current evidence of adverse events associated with dienogest as well as the prevalence of these adverse events during treatment with dienogest.

Methods: Several databases (PubMed, Embase, Cochrane Central and Clinicaltrials.gov, etc.) and the US FDA Adverse Event Reporting System (FAERS) Public Dashboard were searched on May 31, 2023, using the topic words alongside free words of dienogest and "adverse reaction". Studies were incorporated into this research if they reported or assessed safety issues or adverse reactions of dienogest during the period of endometriosis treatment or adenomyosis therapy. The extracted information comprised trial design, dienogest and control group demographics, as well as reported side effects.

Results: This systematic review comprehended 39 publications in total. The mean age of patients in the included studies was 34.43 years. The follow-up duration varied from 3 to 60 months. Most adverse reactions were common and not serious, and the most common adverse reactions during dienogest medication were abnormal uterine bleeding (55%, 95% CI 37-73%), amenorrhea (17%, 95% CI 2-42%) and swelling (13%, 95% CI 3-28%). Uncommon adverse reactions included dysmenorrhea (0.2%, n = 1), dyspepsia (0.4%, n = 1), and (lower) abdominal pain (1%, 95% CI 0-3%), urticaria (1%, 95% CI 0-3%) and peritonitis (1%, n = 1). Serious adverse reactions including decreased lumbar spine Bone Mineral Density (BMD), depression, peritonitis and so on have been reported. Heterogeneity assessment revealed that patient number and study design are influencing factors to adverse reaction prevalence. Moreover, abdominal pain, diarrhea, nausea and vomiting, back pain and anemia are side effects reported both in the FAERS database and in the systematic review.

Conclusions: Dienogest's most frequent side effects were not severe. Dienogest is generally safe for treating endometriosis and adenomyosis. Nevertheless, people should be aware of serious adverse reactions, such as decreased lumbar spine BMD and hemorrhagic shock.